1: /* Copyright (C) 1993,1995-1998,2002,2005 Free Software Foundation, Inc.
    2:    This file is part of the GNU C Library.
    3: 
    4:    The GNU C Library is free software; you can redistribute it and/or
    5:    modify it under the terms of the GNU Lesser General Public
    6:    License as published by the Free Software Foundation; either
    7:    version 2.1 of the License, or (at your option) any later version.
    8: 
    9:    The GNU C Library is distributed in the hope that it will be useful,
   10:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   11:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   12:    Lesser General Public License for more details.
   13: 
   14:    You should have received a copy of the GNU Lesser General Public
   15:    License along with the GNU C Library; if not, write to the Free
   16:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   17:    02111-1307 USA.
   18: 
   19:    As a special exception, if you link the code in this file with
   20:    files compiled with a GNU compiler to produce an executable,
   21:    that does not cause the resulting executable to be covered by
   22:    the GNU Lesser General Public License.  This exception does not
   23:    however invalidate any other reasons why the executable file
   24:    might be covered by the GNU Lesser General Public License.
   25:    This exception applies to code released by its copyright holders
   26:    in files containing the exception.  */
   27: 
   28: #include "libioP.h"
   29: #include <stdio.h>
   30: 
   31: char *
   32: fgets_unlocked (buf, n, fp)
   33:      char *buf;
   34:      int n;
   35:      _IO_FILE *fp;
   36: {
   37:   _IO_size_t count;
   38:   char *result;
   39:   int old_error;
   40:   CHECK_FILE (fp, NULL);
   41:   if (n <= 0)
   42:     return NULL;
   43:   if (__builtin_expect (n == 1, 0))
   44:     {
   45:       /* Another irregular case: since we have to store a NUL byte and
   46:          there is only room for exactly one byte, we don't have to
   47:          read anything.  */
   48:       buf[0] = '\0';
   49:       return buf;
   50:     }
   51:   /* This is very tricky since a file descriptor may be in the
   52:      non-blocking mode. The error flag doesn't mean much in this
   53:      case. We return an error only when there is a new error. */
   54:   old_error = fp->_IO_file_flags & _IO_ERR_SEEN;
   55:   fp->_IO_file_flags &= ~_IO_ERR_SEEN;
   56:   count = INTUSE(_IO_getline) (fp, buf, n - 1, '\n', 1);
   57:   /* If we read in some bytes and errno is EAGAIN, that error will
   58:      be reported for next read. */
   59:   if (count == 0 || ((fp->_IO_file_flags & _IO_ERR_SEEN)
   60:                      && errno != EAGAIN))
   61:     result = NULL;
   62:   else
   63:     {
   64:       buf[count] = '\0';
   65:       result = buf;
   66:     }
   67:   fp->_IO_file_flags |= old_error;
   68:   return result;
   69: }
   70: libc_hidden_def (fgets_unlocked)